A special military board set up by the Obama administration to review the cases of detainees still held at Guantánamo Bay has ruled for the first time that a prisoner remain behind bars indefinitely.

The case of Abdel Malik al-Rahabi was only the second one to come before the new Periodic Review Board, which agreed in January to free another detainee (Mahmoud al Mujahid).

The board decided that Rahabi, originally from Yemen, should not go free in order to “protect against a continuing significant threat to the security of the United States.”

Board members expressed concern that Rahabi was susceptible “to re-engagement” with terrorists if he was released, due to his alleged “significant ties” to al Qaeda and possible involvement in a hijacking plot before being captured by Pakistan’s military in December 2001.

They also cited Yemen’s “marginal security environment” as reason for keeping Rahabi at the prison in Cuba.

Rahabi told the board that he had no desire to harm the U.S. or Americans, and that he just wanted to return home to his family, including his 13-year-old daughter, Ayesha, and go back to farming.

“Being apart from Ayesha has been the hardest part of my detention,” he said, according to the hearing transcript (pdf). “In our calls, she says, ‘I want you to take me to the park; I want you to help me with my homework.’ She sends me five or six letters at a time. I will never again leave Ayesha without her father, my wife without her husband, my parents without their son. I want to make up for the 12 years I have been away.”

His attorney, David Remes, said the board’s concerns about his client were based on “guilt by association.” He told The New York Times that there was “no real basis for concluding that he would be any kind of threat to the United States if he is returned to his family in Yemen.”

The board will review Rahabi’s case again in six months.

Only certain detainees’ cases will be heard by the board, made up of U.S. government officials from national security agencies. Those cases consist of detainees who have not been charged by a military commission and were not approved for transfer by a 2009-2010 task force that Obama set up after becoming president.